There has always been a need in society for verifying a person's identity for a variety of purposes. Modern day scientific technology has adopted the widespread use of computers and related mechanisms for the purposes of giving credit, performing electronic funds transfer, etc. In all facets of the financial community including the retail industry, securities industry, banking, etc., where sums of money, securities and/or materials are to be transferred between owners based on the reliance of one person on the purported identity of another. Electronic systems including various cryptographic instrumentalities together with secret identity numbers or keys provide a certain amount of security, however, the amount of security is predicated upon the degree of secrecy with which one is able to secure his own special identification key. Obviously once a person's key is learned by another, presumably unauthorized person, the other person may falsely assume his identity for a wide variety of electronic applications.
Identity verification by means of signatures has long been known in the art, however, most known systems have various shortcomings. Simply matching the appearance of two signatures is not satisfactory as expert forgers can usually duplicate the appearance of a person's signature as well as the person himself. The result of this is that when an expert forger is involved even expert document examiners are frequently unable to discover that the signature is forged.
Recent developments in the field of automatic signature verification such as exemplified by U.S. Pat. No. 3,983,535 of Herbst et al and U.S. Pat. No. 4,128,829 of Herbst et al both disclose systems which make the concept of personal identification via computer based signature analysis practical. These patents as well as others known in the art compare electrical signals resulting from a person's unique signature dynamics. The two above referenced patents both utilize acceleration and pressure data in making the requisite comparisons and analysis. In such systems the actual analysis or correlation is performed in an electronic computer programmed to perform the requisite correlation algorithm. However, a principal problem with such a system is to provide a pickup device or pen which is durable, has adequate sensitivity for the purpose and which is relatively inexpensive to manufacture as ideally such a pen would be required at every location where it was desired to perform the verification operation.
U.S. patent application Ser. No. 161,483, filed June 20, 1980, entitled "Apparatus for Determining Pen Acceleration," assigned to the same assignee as the present invention, discloses a data input pen for use with a Signature Verification System such as described in the above. The disclosed pen utilizes a special structure for detecting acceleration forces involving variable capacitance transducers. The structure of this patent, although measuring the same forces, discloses a totally different structure from that utilized in the present invention.